Acellular bioactivity and drug delivery of new strontium doped bioactive glasses prepared through a hydrothermal process

The Influence of PEG 4000 on the Physical and Microstructural Properties of 58S Bioactive Glasses

Bioactive glass is currently considered a material with a high biocompatibility and has been used both in the field of bone regeneration and in the preparation of cosmetic products with the controlled release of active compounds. The present work involved a study on the synthesis of bioglass using the sol-gel process. The study aims to evaluate the influence of the treatment of bioglass with Polyethylene glycol 4000 (PEG 4000) on its main characteristics. The surface characteristics of this material were obtained by nitrogen adsorption/desorption analysis, using the standard BET (Brunauer-Emmett-Teller) equation, the crystallinity by XRD (X-ray diffraction) analysis, the surface structure by SEM (Scanning Electron Microscope), thermal stability by TGA (ThermoGravimetric Analyses), and chemical bonds changes by FTIR (Fourier transform infrared) spectroscopy. After treatment with PEG 4000, the average diameter of the pores increased insignificantly, the crystallinity peak disappeared, and the SEM analysis highlighted several clusters of very small sizes.

Multifunctional Sr,Mg-Doped Mesoporous Bioactive Glass Nanoparticles for Simultaneous Bone Regeneration and Drug Delivery

Mesoporous bioactive glass nanoparticles (MBGNs) doped with therapeutical ions present multifunctional systems that enable a synergistic outcome through the dual delivery of drugs and ions. The aim of this study was to evaluate influence of co-doping with strontium and magnesium ions (SrMg-MBGNs) on the properties of MBGNs. A modified microemulsion-assisted sol-gel synthesis was used to obtain particles, and their physicochemical properties, bioactivity, and drug-loading/release ability were evaluated. Indirect biological assays using 2D and 3D cell culture models on human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and endothelial EA.hy926 cells, respectively, were used to determine biocompatibility of MBGNs, their influence on alkaline phosphatase (ALP) production, calcium deposition, and cytoskeletal organization. Results showed that Sr,Mg-doping increased pore volume and solubility, and changed the mesoporous structure from worm-like to radial-dendritic, which led to a slightly accelerated drug release compared to pristine MBGNs. Biological assays confirmed that particles are biocompatible, and have ability to slightly induce ALP production and calcium deposition of hBM-MSCs, as well as to significantly improve the proliferation of EA.hy926 compared to biochemical stimulation via vascular endothelial growth factor (VEGF) administration or regular media. Fluorescence staining revealed that SrMg-MBGNs had a similar effect on EA.hy926 cytoskeletal organization to the VEGF group. In conclusion, Sr,Mg-MBGNs might be considered promising biomaterial for biomedical applications.

Influence of Strontium on the Biological Behavior of Bioactive Glasses for Bone Regeneration

Bioactive glasses (BGs) can potentially be applied in biomedicine, mainly for bone repair and replacement, given their unique ability to connect to natural bone tissue and stimulate bone regeneration. Since their discovery, several glass compositions have been developed to improve the properties and clinical abilities of traditional bioactive glass. Different inorganic ions, such as strontium (Sr2+), have been incorporated in BG due to their ability to perform therapeutic functions. Sr2+ has been gaining prominence due to its ability to stimulate osteogenesis, providing an appropriate environment to improve bone regeneration, in addition to its antibacterial potential. However, as there are still points in the literature that are not well consolidated, such as the influence of ionic concentrations and the BG production technique, this review aims to collect information on the state of the art of the biological behavior of BGs containing Sr2+. It also aims to gather data on different types of BGs doped with different concentrations of Sr2+, and to highlight the manufacturing techniques used in order to analyze the influence of the incorporation of this ion for bone regeneration purposes.

Prosthetic Joint Infections: Biofilm Formation, Management, and the Potential of Mesoporous Bioactive Glass as a New Treatment Option

Infection of prosthetic joints is one of the biggest challenges to a successful replacement of the joint after a total joint arthroplasty. Such infections are caused by bacterial colonies that are difficult to treat by systemic delivery of antibiotics. Local delivery of antibiotics can prove to be the solution to such a devastating outcome that impacts patients' health and ability to regain function in their joints as well as costs the healthcare system millions of dollars every year. This review will discuss prosthetic joint infections in detail with a focus on the development, management, and diagnosis of the infections. Surgeons often opt to use polymethacrylate cement locally to deliver antibiotics; however, due to the rapid release of antibiotics, non-biodegradability, and high chance of reinfection, the search for alternatives is in high demand. One of the most researched alternatives to current treatments is the use of biodegradable and highly compatible bioactive glass. The novelty of this review lies in its focus on mesoporous bioactive glass as a potential alternative to current treatments for prosthetic joint infection. Mesoporous bioactive glass is the focus of this review because it has a higher capacity to deliver biomolecules, stimulate bone growth, and treat infections after prosthetic joint replacement surgeries. The review also examines different synthesis methods, compositions, and properties of mesoporous bioactive glass, highlighting its potential as a biomaterial for the treatment of joint infections.